1. Field of the Invention
The present invention relates to a composite LC element.
2. Discussion of Background
FIG. 1 is a diagram showing a layered film structure of a conventional composite LC element disclosed in, for instance, Japanese Unexamined Patent Publication No. 139619/1984, FIG. 2 is a perspective view partly broken of the composite LC element as shown in FIG. 1 wherein the element is wound around a magnetic core, and FIG. 3 is a diagram showing the equivalent circuit of the composite LC element as in FIG. 2. In FIGS. 1 through 3, reference numerals 1 and 2 designate insulating films, numerals 3, 4 and 5 designate electrode sheets, numerals 3a, 3b, 4a and 5b designate terminals provided at the electrode sheets and a numeral 6 designates a magnetic substance. A composite LC element is formed by winding in a spiral form a layered film structure consisting of the insulating films 1, 2 and the electrode sheets 3, 4, 5 as shown in FIG. 1.
The function of the conventional composite LC element will be described. In FIGS. 1 and 2, a circuit formed between the terminals 3a, 3b functions as an inductance coil and a circuit between the terminals 4a, 5b functions as a capacitance. FIG. 3 shows the equivalent circuit of the element wherein inductance is obtainable between the terminals 3a, 3b and capacitance is obtainable between the terminals 4a, 5b.
As described above, the conventional composite LC element comprises a coil which is formed by winding a single electrode sheet and two insulating films or papers around a core, and a capacitor which is formed by winding two electrode sheets and two insulating films or papers as dielectric substances on the outer circumference of the coil in a concentric manner. Accordingly, the conventional composite LC element is constituted by a coil and a capacitor having an independent distributed constant, and they are simply combined in a concentric manner.